Yemen’s Houthi rebels detained another U.S. Embassy official there. This brings the total number of ex-U.S Embassy staffers in rebel custody to at most 11, according to Yemeni officials.

According to Abdel-Majeed Sabra (a rights lawyer in Sanaa), the Houthis took into custody a former U.S. Embassy press officer last week. They also held a family member of the detainee. Because of fear of reprisals, the family member spoke under condition of anonymity.

Sabra stated that the former embassy press office was being held at the Houthi Security and Intelligence Authority facility. He said that it is not clear whether the Houthis have charged him or any other detainees from U.S Embassy staff.

Sabra stated that the detention of the latest staffer occurred a month after rebels had taken his former deputy from the Embassy.

Houthi rebels took the latest embassy staffer to his home Tuesday to search it and then took him away.

In an email this week to The Associated Press, the State Department stated that the U.S. government had been “unceasing” in its efforts to release the local embassy staffers.

In 2015, Yemen was the most impoverished country on the Arabian Peninsula. Washington closed its Embassy in Yemen.

The Houthis had been driven from their north base by political upheavals the previous year, seizing the capital city and other territories. In 2015, a military coalition led Saudi Arabia joined the war.

With increasing support from Iran the Houthis have been able resist the Saudi-led military alliance. The U.N. and aid agencies consider Yemen’s current situation the worst humanitarian crisis in the world, with millions of Yemenis at risk of starvation.

The Biden administration has repeatedly tried to get the Houthis into peace negotiations, but they have failed. They also accuse the U.S.of supporting the coalition.

The headquarters of the U.S. Embassy was seized by Houthis last October. Many former staff members were detained by the Houthis, but many were later freed.

According to security officials and relatives of detainees, 11 employees from the closed embassy are still in Houthi custody after the latest detention. The official spoke under condition of anonymity as he was not allowed to speak publicly and the family member out of fear of reprisal.

U.N. agencies revealed late last year that two Houthis employees were also detained in Sanaa, in the early November. UNESCO and U.N. human Rights office both confirmed that there were no legal grounds for their detention.

In the past, both sides used detainees to leverage negotiations and prisoner swaps.

This new detention is coming as the Biden administration considers redesigning the Houthis and individual Houthi leaders terrorists. This step carries severe U.S. government sanctions for those who do business with them.

After suffering territorial losses in fighting, Houthis escalated their cross-border attacks with drones and missiles against the United Arab Emirates.

The U.S. imposed new sanctions Wednesday against an Iranian-aligned illicit smuggling network that helped to finance the Houthis. However, it appeared to have stayed short of a terrorist designation.

The United Arab Emirates and Saudi Arabia are pushing for terrorist designation. It could help deter Houthis from attacking and push them towards peace negotiations, according to some Americans and Yemenis.

Some Democratic lawmakers and humanitarian organizations argue that the financial penalties for the designation would have little impact on Houthi leaders, but will drive food suppliers away from the country and risk famine for millions. Twelve Democratic lawmakers wrote to Secretary of State Antony Blinken Wednesday, urging him not to designate terror.